The back cover of the electronic product such as the television, and other components are normally fixed with each other through screws. Currently, in the whole product production line of this kind of electronic product, components are normally fixed with each other through the screws by manual. However, in recent years, the labor cost sharply rises, which causes that the labor cost of mounting screw by manual sharply rises, and the consistency of the product are low due to workers' physical qualities and emotions, furthermore when workers works for a long time, the mounting efficient reduces due to fatigue.